Because obesity is a risk factor for obstructive sleep apnea (OSA), weight loss is recommended for overweight patients with OSA. In a single-center randomized trial, Swedish investigators evaluated a very-low-energy diet for weight loss in 63 obese men (body-mass index, 30–40 kg/m2; age range, 30–65) with moderate-to-severe OSA (apnea-hypopnea index [AHI], 15 events per hour) who were treated with continuous positive airway pressure (CPAP).
Thirty men were assigned to a very-low-energy liquid diet (550 kcal/day) for 7 weeks, followed by 2 weeks of gradual reintroduction of normal food; the others maintained their usual diets for 9 weeks. At baseline, mean AHIs were 37 in both groups. After 9 weeks, the mean weight in the intervention group was 20 kg lower than that in the control group, and AHI was 23 events per hour lower with dieting than without. In addition, 5 men in the intervention group were disease free (AHI <5), and 15 had mild OSA, whereas all but 1 control patient continued to exhibit moderate-to-severe OSA.
Comment: The results of this study are consistent with those of two prior studies (JW Gen Med Mar 10 2009 and Oct 22 2009): Weight loss can be effective for diminishing OSA and might allow some patients to discontinue CPAP, which often is not tolerated well.
— Paul S. Mueller, MD, MPH, FACP
Published in Journal Watch General Medicine January 14, 2010